fix: validate date format in create_schedule with clear error message

tests/test_server.py

@@ -2,6 +2,7 @@ import pytest
 from unittest.mock import MagicMock, patch
 import datetime
 import json
+from fastmcp.exceptions import ToolError
 
 import sys
 from pathlib import Path
@@ -78,6 +79,19 @@ class TestCreateSchedule:
                 },
             )
 
+    async def test_create_schedule_invalid_date_format(self, mcp_client, mock_settings):
+        with pytest.raises(ToolError, match="Invalid date format"):
+            await mcp_client.call_tool(
+                "create_schedule",
+                {
+                    "professional": 6,
+                    "description": "Test appointment",
+                    "customer": 4,
+                    "date": "invalid-date",
+                    "service_center": 11,
+                },
+            )
+
 
 @pytest.mark.asyncio
 class TestFindServiceCenters: